Designing of Long Distance LWPT System for SPS

Laser wireless power transmission (LWPT) is one of the effective ways to provide long-distance convenient and perpetual energy supplies to electronics. Especially in space power satellite (SPS), LWPT can be used to transfer energy not only to ground, but also to other spacecrafts, which applied for satellite rescuing, spacecraft maintaining in orbit. In space application, LWPT system has characteristics of long distance, higher power, precisely aiming accuracy and better adaptability to space environment. In this paper, we propose a long distance LWPT system in SPS. Firstly the system diagram, composition and key technologies are described, which include the selection of laser, the collimated and expanded module of laser beam, the principle of the optical-to-electrical conversion efficiency of InGaAs photovoltaic cell for the high intensity laser with different laser wavelengths, the Acquisition Pointing and Tracking (APT) system and the Maximum Power Point Tracking (MPPT) technology. Then the LWPT system in SPS is designed, which composed of laser transmitting subsystem, laser receiving subsystem, APT platform and energy managing subsystem. Finally, we evaluate the power conversion performance of LWPT by simulation, which illustrates that the system can achieve better energy transmission effect under the condition of transmission distance of 400 km (space to ground) and beam pointing accuracy of 5 μrad.